The present invention relates to lighting effect systems, and in particular to gobo holders for gobo wheels, and to gobo wheels.
Automated illuminating systems are employed in entertainment applications, advertisement applications or architectural applications. Such illuminating systems are light projectors which manipulate a light beam to create different lighting effects.
Common projectors for stage applications, theater applications, architectural applications and other kinds of illumination comprise means for removable insertion of various types of modifiers for an optical beam, namely into the path of a light beam so as to vary the color, intensity, size, shape and structure of the light beam. In a typical system, a light source creates white light passed, for example, through at least one color filter wheel so as to create a colored light beam. Also, the light may be passed through a gobo wheel so as to impress a selected structure upon the light beam. In addition, light intensity wheels are employed for varying the intensity of the light transmitted. Also, there are means which represent a mechanical iris in order to determine the beam size. Moreover, there are also lens systems for controlling the focus of the light beam and the divergence of the light beam. Also, effect wheels are used for being placed into the light beam so as to then create a flame or similar effects, for example, by a concerted action of a gobo wheel and an effect wheel.
U.S. Pat. No. 6,601,973 discloses a system and a method for replacing gobos within a compact projector which has rotatable gobo holders provided therein which may simply be mounted to or removed from a gobo carrousel or gobo wheel. Such a gobo wheel comprises a rotatable base plate, a central planetary gear and a spring holder at the base plate, said spring holder being configured to elastically accommodate a gobo holder.
The base plate may comprise six openings arranged around a central axis of the base plate and spaced apart from one another at the same time. These openings, or some of these openings, can accommodate one gobo holder each. The base plate further comprises a central hub extending outward from a surface of the base plate to be mounted to a rotatable shaft of a motor so as to rotate the base plate such that one of the gobo holders will be positioned within the light path.
Moreover, a spring holder is mounted to the base plate. In addition, a central planet wheel is coupled to a drive motor via a rotatable shaft. In this manner, the drive motor rotates with the entire gobo base plate, whereas the planet wheel, which has an axis which coincides with the axis of the hub, is able to be rotated independently of the rotation of the base plate. Typically, a circumferential edge of the central planet wheel has cogs formed around it which engage with gears which are each arranged on a gobo holder around the circumference of same, such that the gobo holders are rotated when the planet wheel is rotated.
Each gobo holder comprises a gobo fastener, which comprises a cylindrical portion having first and second ends. An annular plate defines an opening. In addition, a projecting plate is formed within the inner circumference of a cylindrical portion adjacent to a second end. A spring is used for being able to reliably and efficiently fasten a gobo to the gobo holder.
WO 2004/046607 A1 also discloses a gobo wheel which has replaceable segments comprising gobos arranged thereon. These replaceable segments are gobo holders comprising a base plate which is formed as a shaped lamella. The base plate has a bearing fixedly mounted to it by means of which a gear, to which a gobo may be connected, may be rotated in relation to the base plate. A shaped lamella at the base plate is configured to engage with a central holder riveted onto the gobo wheel. In particular, the central holder comprises one finger for each base plate. Also, recesses are provided within the base plate for alignment purposes, which, once a gobo holder has been inserted, engage with respective alignment studs, or cylindrical heads of screws. The gobo holder is held by means of the elastic action of the spring finger.
Well-known possibilities of fastening a gobo holder to a gobo wheel thus consist in that an elastic element is provided which is fixedly connected to the gobo wheel and which, when a gobo holder is mounted, is deflected and exerts a spring force on the gobo holder. The gobo holder itself, by contrast, is not configured to be elastic, but to be rigid.
On the other hand, increasing requirements placed upon such automated light systems, which are also referred to as “moving heads”, entail ever-increasing demands for flexibility and more and more lighting effects. This results in that since quite a long time ago, one can no longer assume that one single process of populating a gobo wheel with several gobo holders, and thus various gobos, would meet all needs. Instead, a significantly larger number of gobos are typically provided than have room on one gobo wheel. In order to be able to create the gobo lighting effects desired for specific applications, the gobos desired by the light artist are therefore incorporated into the lamp prior to using a “moving head”. Replacing the gobos themselves is not an option, since being continuously installed into and de-installed from a gobo holder is something that gobos would not survive for long.
As a result, the only option remaining is to replace gobo holders, as is described in the previously cited documents. This results in that the spring suspension of the gobo wheel is constantly under stress because of the frequent engaging and disengaging of the gobo holders on the gobo wheel. The spring members become weaker over time, which in the extreme case may result in that the gobo holders are no longer reliably fastened to the gobo wheel, and that at some point a gobo wheel will be replaced. However, these are unpleasant and costly repairs which are problematic particularly also in that they lead to additional idle time.
Such “moving heads” are typically no longer bought on a large-scale basis, but are rented from an event organizer for specific installations. However, lenders of a moving head can only work in a cost-covering or profitable manner if their moving heads have no idle times. However, if the spring fixtures on the gobo wheel slacken more and more due to frequent replacement of gobo holders, repairs would be needed at some point in that entire gobo wheels would have to be replaced because maybe only one single spring member of a gobo holder which was to be replaced is defective. In addition, this problem is aggravated in that, in particular in rental applications, gobo applications often entail inexpert handling of the moving heads and of the sensitive components, which leads to a significantly higher probability of damage occurring as compared to any situation where such a moving head is carefully handled by trained qualified personnel only.